It is advantageous, for example, to be able to transmit new disks which have been released during the month in high-fidelity sound. A similar problem can arise for transmitting new images.
Means for permanently archiving data currently exist, e.g. non-erasurable digital optical disks (write once, read many or "WORM"), compact disks (or "CD ROM"), or "audio" compact disks. It is difficult to see how monthly issues of new releases can be demonstrated by distributing such storage media.
The aim of the present invention is to enable such distribution to take place using a system which can be rerecorded n times, such as one or more magnetic disks.
The problem is thus one of delivering bulk data in real time, at a rate which may be as much as 768 kilobits per second, and this distribution is to be performed simultaneously for a fairly high number of simultaneous users, for example at least 16 consultation stations It is also necessary for the system to be capable of handling several gigabytes of mass memory.
Computer servers are already known. In such servers, a computer searches through data in a mass memory such as a magnetic disk or an optical disk and then transmits the data over one or more outlets, causing said data to transit through its own registers or central memory.
Using such a server, the theoretical speed limit for processing data is equal to about one half of the maximum bus speed. In practice, the speed is much less than that since the bus must also convey communications between the processor and its peripherals.
For example, in order to process 16 outlets at a rate of 384 kilobits per second, it would be necessary to have a bus operating at least 2 megabytes per second, and such buses are to be found only in very large and very expensive systems. This explains why the market for servers, and in particular for multi-outlet servers, does not provide a server having the capacity to deliver information at 384 kilobits per second, for example.
Preferred embodiments of the present invention provide a solution to this problem by proposing a multi-outlet server of novel structure which is suitable for operating over a wide band, i.e. at a high transmission rate.